摘要:
The automatic and optimal selection of coding parameter values according to analyses of coding trials is disclosed. The Neural Encoding Model (NEM) provides a method for providing a quantitative measure of the likelihood that a human observer can distinguish an original sensory signal from an approximation thereof, thus providing a metric by which the effect of various coding parameters may be analyzed and optimized. Optimal coding parameters can be defined for an entire data set, such as a digitized audio file, or for discrete portions of the data set. A trial coded data set or portion thereof is analyzed to determining if certain coding parameters have been assigned optimal values. If not, parameter manipulation is performed in an intelligent order and the objective analysis is repeated until predetermined objective perceptual distance criteria are achieved.
摘要:
Source signals, such as audio and/or video data, are encoded into multiple, consecutive frequency bands. These bands are referred to as coding layers. Rather than performing complex bit-slice operations, a disclosed technique enables an agile and simplified response to transmission channel throughput variations. Specifically, if it becomes necessary to restrict the rate of data transmission to avoid receiver buffer underflow resulting from transmission channel degradation, layers from the transmitted signal are omitted, beginning with the highest frequency bands. Efficient and agile bit rate scalability during data streaming through wired or wireless networks and during local playback is thus enabled.
摘要:
A method for improving precision in FFT calculations. For each iteration in an FFT implementation, a constant normalization multiplier is inserted such that the dynamic ranges of the input and output are the same. The final FFT output is multiplied by a constant normalization factor given by the number of iterations and the constant normalization multiplier.
摘要:
Round-off error in fixed-point arithmetic is minimized by changing the magnitudes of two multipliers simultaneously. The dynamic range of an intermediate output is thus maximized to increase computation precision. A much smaller round-off error, caused by fixed-point arithmetic, thus results.
摘要:
The dynamic streaming of multimedia data between a data server and one or more clients is disclosed. Dynamic streaming enables the rapid and accurate characterization of the end-to-end path conditions in a server-client streaming session, as well as the rapid and intelligent response to those conditions in terms of source compression prior to data packetization. The most significant bits of an original bit stream can be adaptively and immediately selected in response to network conditions. The adaptive selection process is informed by feedback from the client receiver indicative of a time-to-transit the network from server to client. A control protocol and server architecture, including file format, data structure, data processing procedures, cache control mechanisms, and adaptation algorithms useful in implementing dynamic streaming are also disclosed.